Endoscopic sheath assembly and associated method

ABSTRACT

An endoscope sheath includes a web member disposable in a tubular configuration in engagement with an endoscope insertion member, the member being provided with a tear string in the form of a tensile member. The tear string preferably extends longitudinally along the web member. In addition, the tear string preferably extends from one end of the web member to an opposite end thereof and is disposed along a weakened area of the web member. The web member is provided in a plurality of regions with a layer of adhesive material. The adhesive material of at least one of the regions is permanent adhesive, whereas the adhesive material of at least another of the regions forms a separable bond. These regions extend along opposing longitudinal edges of the web member.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a medical device and to an associatedmedical technique. More particularly, this invention relates to anendoscopic sheath assembly and to an associated endoscopic method.

[0002] Flexible endoscopes are inserted into the digestive tract fordiagnostic and therapeutic purposes. Endoscopes generally include alight guide for transmitting optical-wavelength electromagneticradiation into the patient. Images are captured, typically via lensesand an optical fiber bundle or a charge-coupled device, whereby a usercan visually inspect the inner walls or surfaces of the digestive tract.One common objective of endoscopic investigations in the digestive tractis to detect the presence of polyps. Where a polyp is visually detected,particularly in the colon, it should be severed, captured, and removedfrom the patient. Alternatively, particularly where the polyp may be amalignant cancer, the polyp may be severed and captured for extractionfrom the patient.

[0003] One problem in endoscopy is the potential for the transmission ofinfection from one patient to another because of remaining bioburdeninside or on the endoscope. Traditionally, this problem is countered bythoroughly cleaning the instrument. However, it is difficult toadequately clean an endoscope, particularly the biopsy channel thereof.One solution has been to encase the endoscope insertion member in adisposable sheath which is sealed to prevent the accumulation ofbioburden inside or on the endoscope. Such a sheath is made of a verydelicate thin material and is long, flimsy and very narrow. To securelyapply the sheath to an endoscope without ripping the sheath isdifficult. Removing a sheath from an endoscope without contaminating theendoscope is also difficult.

OBJECTS OF THE INVENTION

[0004] It is a general object of the present invention to provide animproved endoscope sheath or sheath assembly.

[0005] A further object of the present invention is to provide such asheath which is inexpensive and/or easy to use.

[0006] It is an even more specific object of the present invention toprovide such a sheath which is particularly suitable for use withflexible endoscopes during investigations of the digestive orgastro-intestinal tract and which may be used in investigations of anyinternal body cavity.

[0007] A further objective is to minimize the amount of time it takes toreprocess an endoscope between successive procedures.

[0008] These and other objects of the invention will be apparent fromthe drawings and descriptions herein. Although every object of theinvention is attained by at least one embodiment of the invention, thereis not necessarily any one embodiment that achieves all of the objectsof the invention.

SUMMARY OF THE INVENTION

[0009] An endoscope sheath in accordance with the present inventionincludes a web member disposable in a tubular configuration inengagement with an endoscope insertion member, the member being providedwith a tear string in the form of a tensile member. The tear stringpreferably extends longitudinally along the web member. In addition, thetear string preferably extends from one end of the web member to anopposite end thereof and is preferably disposed along a weakened area ofthe sheath to facilitate the severing of the sheath by the tear string.

[0010] The sheath is preferably provided with an end cap securable overa distal tip of the endoscope insertion member in a fluid tightengagement with the web member. The end cap is secured or securable toan end of the web member.

[0011] Pursuant to another feature of the present invention, the webmember is provided in at least one region with a layer of adhesivematerial. The adhesive material of that region is preferably permanentadhesive. Optionally, the web member may be provided in one or moreadditional regions with a layer of adhesive material. The adhesivematerial of these other regions forms a separable bond. In oneembodiment of the invention, two adhesive regions extend along opposinglongitudinal edges of the web member, at least where web member is arectangular sheet.

[0012] A medical method in accordance with the present inventioncomprises providing an endoscope insertion member, providing a sheath inthe form of a web or sheet, wrapping the sheath about at least a distalend portion of the insertion member, adhesively fastening the sheathabout the insertion member, inserting the insertion member with thesheath wrapped thereabout into a patient, and subsequently removing theinsertion member with the sheath wrapped thereabout from the patient.The sheath may then be removed from the endoscope insertion member, forinstance, by pulling a tear string embedded in the sheath to sever thesheath along a predetermined line where the sheath is weakened (e.g., ascore line), and subsequently separating the insertion member and thetorn or severed sheath from one another.

[0013] The fastening of the sheath may include removing at least oneprotective cover strip from the sheath to uncover at least one adhesiveregion and subsequently pressing the adhesive region against theinsertion member. After the wrapping of the sheath about the endoscopeinsertion member, the adhesive region is placed into contact with anouter surface of the sheath and pressed against the endoscope insertionmember. This adhesive layer preferably forms a permanent bond. Where thesheath is provided in another region with a layer of nonpermanentadhesive, this region is placed into direct contact with the sheath.Subsequently, a portion of the sheath bearing the permanent adhesivelayer is wrapped over the region in direct contact with the sheath.

[0014] The wrapping of the sheath includes, pursuant to a preferredfeature of the invention, providing a cradle member having a groove,placing the web or sheet over the cradle member so that a portion of theweb or sheet lies in the groove, disposing the endoscope insertionmember on the portion of the web or sheet lying in the groove, andwinding a side portion of the web or sheet about the endoscope insertionmember after the disposing thereof on the web or sheet. This techniquefacilitates application of the sheath in that the endoscope insertionmember is partially surrounded by the sheath in the cradle member andthe operator or user need only fold the longitudinal edge portions overone another and press the adhesive regions to effectuate an effectivelysecure closure.

[0015] The fastening of the sheath to the endoscope insertion member mayinclude, pursuant to a particular feature of the present invention,adhesively securing a first longitudinal edge region of the web or sheetto an outer surface of the endoscope insertion member, and subsequentlyadhesively securing a second longitudinal edge region of the web orsheet to on outer surface of the web or sheet.

[0016] The sheath may include built-in or insertable biopsy, suction andirrigation channels or any combination thereof or may include spacealong the length of the sheath to allow addition of said channels whichmay be comprised of tubing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a schematic exploded isometric view of an endoscopicsheath assembly in accordance with the present invention utilizable inthe procedures of FIGS. 8A-8H and 9A-9H.

[0018]FIGS. 2A-2D are schematic isometric views of an endoscopicinsertion shaft and the sheath assembly of FIG. 1, showing successivesteps in the application of the sheath assembly to the endoscopeinsertion shaft, in accordance with the present invention.

[0019]FIG. 3 is a detail schematic isometric view of a portion III ofthe sheath of FIG. 2A, on a larger scale.

[0020]FIG. 4 is a schematic isometric view of a support, in accordancewith the present invention, for an endoscope insertion member, to aid inthe application process of FIGS. 2A-2D.

[0021]FIG. 5 is a schematic isometric view, of a modified endoscopicsheath assembly in accordance with the present invention, showing a stepin the application of the sheath assembly to an endoscope insertionshaft.

[0022]FIG. 6 is a detail view, on a larger scale, of a distal end of thesheath assembly of FIG. 5.

[0023]FIG. 7 is a schematic end elevational view, on an even largerscale, of the sheath assembly of FIG. 5.

[0024]FIG. 8 is a schematic isometric view of a sheath assembly inaccordance with the present invention on an endoscope insertion shaft,showing a stage in the removal of the sheath assembly from the endoscopeinsertion shaft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] As depicted in FIG. 1, an endoscopic sheath assembly 178 includesan endoscope sheath 180 in the form of a web member or sheet and furtherincludes an endoscope end cap 182. Sheath 180 is provided with a layerof adhesive material 184, 186, 188 along a forward end region, a firstlongitudinal edge region and a second longitudinal edge region,respectively (not separately enumerated). Sheath 180 is further providedalong an elongate weakened (e.g., thinned or scored) region (notseparately labeled) with an embedded tensile member 190 such as a tearstring for enabling a severing of the sheath in preparation for removalof the sheath from an endoscope insertion member 192 (FIG. 2A).Releasable protective cover strips 194, 196, 198 are removably attachedto the adhesive layers or regions 184, 186, 188. Preferably, theadhesive material of layers or regions 184 and 186 is a permanentadhesive, while the adhesive material of layer or region 188 forms aseparable or releasable bond. Optionally, sheath 180 includes one ormore built-in or insertable biopsy, suction and irrigation channels 199or may include space along the length of the sheath to allow addition ofsaid channels which may be comprised of tubing.

[0026] In applying endoscopic sheath assembly 178 to endoscope insertionmember 192 (FIG. 2A), end cap 182 is first placed over a distal tip 200of the insertion member. End cap 182 includes a substantially rigidcollar 202 and a transparent plate 204. End plate 204 transmitsillumination into a patient from a light outlet 206 on endoscope tip200. Returning light passes through plate 204 and impinges on a lens208.

[0027] After the placement of end cap 182 over distal tip 200 ofinsertion member 192, protective cover strip 198 is peeled away fromlongitudinal adhesive layer 188. In addition, protective cover strip 194(see FIG. 3) is removed from adhesive layer 184. Adhesive layer 188 isaligned longitudinally with endoscope insertion member 192 with thelatter in a straight configuration, parallel to an axis thereof.Adhesive layer 188 is pressed against insertion member 192. Then thedistal end of sheath or web member 180 is wrapped around collar 202, asshown in FIG. 2B, so that adhesive layer 184 permanently bonds to endcap 182. Prior to completing the wrapping of the distal end of sheath orweb member 180 about collar 202, protective cover strip 196 is peeledaway from longitudinal adhesive layer 186 (see FIG. 3). The uncoveredlayer 186 of permanent adhesive is then placed into an overlappingconfiguration with the sheath or web 180 and bonded thereto (FIG. 2C) sothat the sheath surround the endoscope insertion member 192 in tightfluid-sealed fit (FIG. 2D).

[0028] An alternative method of applying sheath assembly 178 toendoscope insertion member 192 utilizes a support cradle 210 shown inFIG. 4. Support cradle 210 has a groove 212 of equivalent diameter toinsertion member 192. First sheath or web member 180 with at leastprotective cover strip 194 removed is laid into groove 212. Endoscopeinsertion member 192 with end cap 182 positioned thereon is then placedatop sheath 180 so that collar 202 engages exposed adhesive layer 184.At this time, protective cover strip 198 may be removed to exposeadhesive layer 188 which is then pressed along insertion member 192.Subsequently, strip 196 is removed to expose permanent-adhesive layer186 which is then bonded to an outer surface of the sheath or web 180.

[0029] In an alternative sheath assembly 214 shown in FIG. 5, a sheathor web member 216 is attached to an end cap 218 during manufacture.Sheath or web 216 is provided along part of a first longitudinal edgewith a layer 220 of lightly bonding adhesive covered by a releasableprotective strip 222. Sheath or web 216 is provided along part of asecond or opposing longitudinal edge with a layer 224 of permanentlybonding adhesive covered by a releasable protective strip 226. A tearstring 228 is embedded in sheath or web 216 and extends longitudinallytherealong. Along a distal end portion of sheath assembly 214, theopposing longitudinal edge regions of the sheath or web 216 overlap andare bonded to one another, prior to introduction of an endoscopeinsertion member 230 into the sheath assembly, as shown in FIGS. 5 and16.

[0030]FIG. 8 depicts an initial step in the removal of a sheath assembly106, 146, 178, 214 from an endoscope insertion member (not separatelylabeled). A tear string 190, 228 is manually grasped and pulled to severor rip the respective sheath 112, 152, 180, 216 along a straight orcurved line extending at least a substantial portion of the length ofthe endoscope insertion member. The rip or tear in the sheath 112, 152,180, 216 is preferably formed in a direction from the proximal end tothe distal end of the instrument.

[0031] A sheath as discussed hereinabove with reference to the drawingfigures, provides the benefit of keeping the endoscope relatively freefrom contact with the patient's body fluids or fecal material. Thesheath is made of a thin flexible material that is split from itsproximal end to the distal end or to a point close to the distal end.One side of the split line has a permanent adhesive component thatsufficiently overlaps the other side of the sheath to enable fixation ofthe sheath to an endoscope insertion member. The adhesive can be coveredby a removable protective strip that is simply peeled off to expose theadhesive layer. The sheath is then wrapped over the endoscope andadhered to the non-adhesive side of the sheath, making a secure andfluid tight bond the entire length of the sheath. In order to easilyapply a long and narrow sheath in accordance with the invention to anendoscope, the non-adhesive part of the sheath is first lightly bondedto the insertion shaft of the endoscope by means of a light-adhesiveregion also covered by a removable protective strip. Only once the firstside is lightly bonded to the endoscope is the strip overlying thepermanent glue remove. That side is then folded over the first side andpemanently attached as described above. The sheath also contains anembedded tear-strip with a small portion of the tear-strip exposed,e.g., at the proximal end of the sheath, so as to facilitate grabbing ofthe tear strip and pulling it lengthwise down the sheath causing thesheath to easily split and be safely, cleanly and easily removed fromthe endoscope.

[0032] The distal end of the sheath is provided or associated with anend cap in the shape of a short tube that incorporates a transparent endportion that fits over the distal end of the endoscope insertion shaft,allowing for use of the endoscope's visualization capabilities andpotentially the working channels of the endoscope.

[0033] Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. For example, a sheath might be provided with only asingle region of adhesive that serves to bond part of the sheath to anunderlying portion of the sheath placed in direct contact with anendoscope insertion member. Although a tear string is preferablyincorporate into a sheath, the tear string may be omitted where someother means of sheath removal is provided.

[0034] It is to be noted that a tear string or tensile member as thoseterms are used herein may cover a string, a wire, a reinforced,strengthened or thickened area of the sheath, etc.

[0035] Accordingly, it is to be understood that the drawings anddescriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

1. An endoscope sheath assembly comprising a web member provided with anembedded tensile element for enabling a severing of said web member inpreparation for removal of said web member from an endoscope insertionmember.
 2. The sheath assembly defined in claim 32, further comprisingat least one releasable protective cover strip removably attached to theadhesive layer of said region.
 3. The sheath assembly defined in claim1, further comprising an end cap securable over a distal tip of saidinsertion member in a fluid tight engagement with said web member. 4.The sheath assembly defined in claim 1, further comprising an end capsecured to an end of said web member.
 5. The sheath assembly defined inclaim 32 wherein the adhesive material of said region is permanentadhesive.
 6. The sheath assembly defined in claim 5 wherein said regionis one region and said web member is provided in another region with alayer of adhesive material forming a separable bond.
 7. The sheathassembly defined in claim 6 wherein said one region extends along alongitudinal edge of said web member, said another region extendingalong an opposite longitudinal end of said web member.
 8. The sheathassembly defined in claim 32 wherein the adhesive material of saidregion forms a separable bond.
 9. The sheath assembly defined in claim 8wherein said region extends along one of a long or longitudinal edge anda short or transverse edge of said web member.
 10. The sheath assemblydefined in claim 1 wherein said web member is a rectangular sheet and isprovided in at least two regions with respective layers of adhesivematerial, said regions being disposed along edges of said sheet.
 11. Thesheath assembly defined in claim 10 wherein two of said regions aredisposed along opposing longitudinal edges of said sheet.
 12. The sheathassembly defined in claim 11 wherein an end cap is secured to atransverse edge of said sheet extending perpendicularly to saidlongitudinal edges.
 13. The sheath assembly defined in claim 1 whereinsaid tensile element extends longitudinally along said web member. 14.The sheath assembly defined in claim 13 wherein said tensile elementextends from one end of said web member to an opposite end of said webmember.
 15. The sheath assembly defined in claim 1 wherein said tensileelement extends along a weakened region of said web member.
 16. Thesheath assembly defined in claim 32 wherein said web member is providedwith a further layer of adhesive in a region along a short or transverseedge of said web member, further comprising an end cap securable to saidweb member via said further layer of adhesive.
 17. The sheath assemblydefined in claim 1 wherein said web member is provided with at least onechannel.
 18. A medical method comprising: providing an endoscopeinsertion member; providing a web or sheet; wrapping said web or sheetabout at least a distal end portion of said insertion member to form asheath; adhesively fastening said sheath about said insertion member;inserting said insertion member with the sheath wrapped thereabout intoa patient; and subsequently removing said insertion member with thesheath wrapped thereabout from the patient.
 19. The method defined inclaim 18 wherein the fastening of said sheath includes removing at leastone protective cover strip from said web or sheet to uncover at leastone adhesive region and subsequently pressing said adhesive regionagainst said insertion member.
 20. The method defined in claim 18,further comprising providing an end cap and attaching said end cap to adistal tip of said insertion member prior to inserting of said insertionmember and said sheath into the patient, said end cap being alsoinserted into the patient.
 21. The method defined in claim 18 whereinthe wrapping of said sheath includes: providing a cradle member having agroove; placing said web or sheet over said cradle member so that aportion of said web or sheet lies in said groove; disposing saidendoscope insertion member on the portion of said web or sheet lying insaid groove; and winding a side portion of said web or sheet about saidendoscope insertion member after the disposing thereof on said web orsheet.
 22. The method defined in claim 18 wherein the fastening of saidsheath to said endoscope insertion member includes: adhesively securinga first longitudinal edge region of said web or sheet to an outersurface of said endoscope insertion member; and subsequently adhesivelysecuring a second longitudinal edge region of said web or sheet to anouter surface of said web or sheet.
 23. The method defined in claim 18,further comprising: after the removal of the insertion member and thesheath from the patient, pulling a tear string embedded in said sheathto sever said sheath along a predetermined line; and after the pullingof the tear string, separating the insertion member and the torn orsevered sheath from one another.
 24. The method defined in claim 23wherein said tear string is disposed along a weakened region of saidsheath, the pulling of said tear string severing said sheath along saidweakened region.
 25. An endoscope sheath including a web memberdisposable in a tubular configuration in engagement with an endoscopeinsertion member, said web member being provided with a tear string. 26.The sheath defined in claim 25, further comprising an end cap securableover a distal tip of the endoscope insertion member in a fluid tightengagement with said web member.
 27. The sheath defined in claim 25,further comprising an end cap secured to an end of said web member. 28.The sheath defined in claim 25 wherein said tear string extendslongitudinally along said web member.
 29. The sheath defined in claim 25wherein said tear string extends from one end of said web member to anopposite end of said web member.
 30. The sheath defined in claim 25wherein said tear string extends along a weakened region of said webmember.
 31. The sheath defined in claim 25 wherein said web member isprovided with at least one channel.
 32. The sheath assembly defined inclaim 1 wherein said web member is further provided in at least oneregion with a layer of adhesive material.
 33. The sheath assemblydefined in claim 1 wherein said web member is disposable in a tubularconfiguration about an endoscope insertion member.
 34. A medical methodcomprising: providing an endoscope insertion member; providing a sheath;disposing said sheath about at least a distal end portion of saidinsertion member; inserting said insertion member with the sheathwrapped thereabout into a patient; subsequently removing said insertionmember with the sheath wrapped thereabout from the patient; after theremoval of the insertion member and the sheath from the patient, pullinga tear string embedded in said sheath to sever said sheath along apredetermined line; and after the pulling of the tear string, separatingthe insertion member and the torn or severed sheath from one another.35. The method defined in claim 34, further comprising providing an endcap and attaching said end cap to a distal tip of said insertion memberprior to inserting of said insertion member and said sheath into thepatient, said end cap being also inserted into the patient.